Apparatus for measure of quantity and associated method of manufacturing

ABSTRACT

In embodiments, it is provided an integrated device for providing a measure of a quantity dependent on current through an electrical conductor, having: a sensing and processing sub-system; an electrical conductor to conduct a current; an insulating material encapsulating the sensing and processing sub-system and maintaining the electrical conductor in a fixed and spaced relationship to the sensing and processing sub-system, wherein the insulating material is configured to insulate the electrical conductor from the sensing and processing sub-system; sensing circuitry comprising a plurality of magnetic field sensing elements arranged on the sensing and processing sub-system adjacent to the electrical conductor, wherein the sensing circuitry is configured to provide a measure of the quantity as a weighted sum and/or difference of outputs of the magnetic field sensing elements caused by the current flowing through the electrical conductor adjacent to the plurality of magnetic field sensing elements; a voltage sensing input for sensing a measure of voltage associated with the current conductor; and output circuitry on the sensing and processing sub-system arranged to provide an output measure of the quantity from the sensed measure of current and sensed measure of voltage.

The present disclosure relates to measuring devices and related methods,more particularly to integrated devices, still more particularly toIntegrated devices for providing a measure of quantities dependent onthe current through a conductor, such as the active and reactive power.

Devices for power measurement are known in the art. Conventionally, theuse of a separate current and a separate voltage sensor and a separateprocessing device is required. In some known examples, the currentsensor may be a shunt resistor, a current transformer, a Rogowski coilor a discrete Hall element. Traditionally, the output of each of thecurrent and voltage analog sensors must be passed through anAnalog-to-Digital converter and transferred to a microprocessor,microcontroller, digital signal processor or similar device whichmultiplies the two digital measures, and numerically integrates them.

The known devices have drawbacks. They are generally bulky and consume alot of space. This makes power measurement infeasible in situationswhere space is scarce, as e.g. in the socket of a smart light bulb, in asmart plug, in a smart socket, or in other miniaturized devices.

A large number of external components is generally required in the knowndevices. These must be assembled, and the final module assembly must betested and calibrated. As well as consuming space, this is costly andtime consuming. This makes power measurement infeasible where cost is anissue, e.g. in high volume low cost consumer devices.

The metrology knowledge required to get the known devices to workaccurately is difficult and requires specific domain expertise. Theremay be a phase shift between the readings of the voltage and the currentsensors, quantisation errors, offsets and temperature dependence, whicheither result in poor metrology or must be carefully compensated for.This makes power measurement infeasible where specialist domainexpertise is either not available or available only on prohibitive termsrelative to the primary requirements of the application.

The known devices, discrete Hall elements, current transformers andRogowski coils particularly, are vulnerable to interference from strayelectromagnetic fields, and must be shielded. Furthermore, discrete Hallelements may suffer from noise and require a field concentrator toimprove the signal-to-noise ratio. This is costly and space consuming.

While the method of differential field sensing by the use of two sensorsis known (at least in the context of current measurement) to the personskilled in the art and offers partial rejection of stray electromagneticfields without shielding, this method works only for rejection of strayelectromagnetic fields which are spatially constant (as well as, whenexternal discrete current sensors are used, adding to cost and spaceusage). In particular, the method does not work well for certain commonstray electromagnetic fields such as high frequency electromagneticfields and electromagnetic fields generated by nearby currentconductors. In particular, the method does not work sufficiently well(without shielding) to meet metering standards mandated of domestic andindustrial meters by certain national standards bodies (such as ANSI andIEC).

Shunt resistor sensors give a current reading which is live, so thecustomer-facing electronics must be isolated from the energy sensingpart with optocouplers or other isolators. Likewise, use of shuntresistor current sensors in polyphase energy measurement requiresisolation of readings from the different phases with isolators of thesame kind.

Aspects, embodiments and examples of the disclosure are defined in theappended claims.

Aspects and embodiments of the disclosure are also described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1 shows perspective pictures of two faces of a first example of apower measurement device;

FIG. 1A shows a schematic illustration of a cross section of the powermeasurement device in FIG. 1;

FIG. 1B shows a more detailed schematic view of selected components ofthe device in FIG. 1;

FIG. 2 shows a picture of a second example of a power measurementdevice;

FIG. 2A shows a schematic illustration of a cross section of the powermeasurement device of FIG. 2;

FIG. 2B shows another schematic representation of the device in FIG. 2;

FIG. 2C shows another schematic representation of the device in FIG. 2;

FIG. 3 shows a picture of a third example of a power measurement device;

FIG. 3A shows a schematic illustration of a cross section of the powermeasurement device of FIG. 3;

FIG. 4 shows a schematic representation of an example part of a powermeasurement device;

FIG. 4A shows a schematic representation of the part of a powermeasurement device in FIG. 4 with a more specific assignment of theinput-outputs;

FIGS. 4B to 4E show schematic representations of the part of a powermeasurement device in FIG. 4A with only some input-outputs implemented:

FIG. 5 shows a more detailed schematic view of the parts in FIGS. 4 to4E;

FIG. 5A shows a more detailed schematic view of selected components ofthe parts in FIGS. 4 to 4E;

FIG. 6 shows a schematic representation of the part in FIG. 4encapsulated as a chip in an integrated circuit package:

FIG. 6A shows a schematic representation of the part in FIG. 4Aencapsulated as a chip in an integrated circuit package;

FIG. 6B shows a schematic representation of the part in FIG. 4Bencapsulated as a chip in an 8-pin integrated circuit package;

FIGS. 6C and 6D show schematic representations of the part in FIG. 4Cencapsulated as a chip in a 14-pin and an 8-pin integrated circuitpackage, respectively;

FIG. 6E shows a schematic representation of the part in FIG. 4Dencapsulated as a chip in an 8-pin integrated circuit package;

FIG. 6F shows a schematic representation of the part in FIG. 4Eencapsulated as a chip in a 12-pin integrated circuit package;

FIG. 7 shows a schematic representation of a device comprising the partin FIG. 4 encapsulated as a chip in an integrated circuit package withan integrated conductor, as per FIG. 1;

FIG. 7A shows a schematic representation of a device comprising the partin FIG. 4A encapsulated as a chip in an integrated circuit package withan integrated conductor, as per FIG. 1;

FIG. 7B shows a schematic representation of a device comprising the partIn FIG. 4B encapsulated as a chip in a 4-pin integrated circuit packagewith an integrated conductor, as per FIG. 1;

FIG. 7C shows a schematic representation of a device comprising the partin FIG. 4C encapsulated as a chip in a 12-pin integrated circuit packagewith an integrated conductor, as per FIG. 1;

FIG. 7D shows a schematic representation of a device comprising the partin FIG. 4D encapsulated as a chip in a 6-pin integrated circuit packagewith an integrated conductor, as per FIG. 1;

FIG. 7E shows a schematic representation of a device comprising the partIn FIG. 4E encapsulated as a chip in a 6-pin integrated circuit packagewith an integrated conductor, as per FIG. 1;

FIG. 7F shows a schematic representation of a device comprising the partin FIG. 4F encapsulated as a chip in an 8-pin integrated circuit packagewith an integrated conductor, as per FIG. 1;

FIG. 8 shows a schematic representation of a power measurement device asin FIGS. 2 to 2C comprising the part in FIG. 4E or the encapsulated partin FIG. 6F;

FIG. 10 shows a schematic representation of a power measurement deviceas in FIGS. 1 to 1B comprising the device in FIG. 7F;

FIGS. 9A to 9F, and 11A to 11F show schematic representations ofelectromechanical meters; in which

FIG. 9A shows a schematic illustration of an example electromechanicalmeter comprising the part in FIG. 4C or the encapsulated part in FIG. 6Din a single phase application, measuring positive energy flow only;

FIG. 9B shows a schematic illustration of an example electromechanicalmeter comprising the part in FIG. 4C or the encapsulated part in FIG. 6Cin a single phase application, measuring both positive and negativeenergy flow; and

FIG. 9C shows a schematic illustration of an example electromechanicalmeter comprising the part in FIG. 4C or the encapsulated part in FIG. 6Cin a single phase dual-tariff application, measuring positive energyflow only; and

FIG. 9D shows a schematic illustration of an example electromechanicalmeter comprising the part in FIG. 4C or the encapsulated part in FIG. 6Din a three phase application, measuring positive energy flow only; and

FIG. 9E shows a schematic illustration of an example electromechanicalmeter comprising the part in FIG. 4C or the encapsulated parts in FIGS.6C and 6D, in a three phase application, measuring both positive andnegative energy flow; and

FIG. 9F shows a schematic illustration of an example electromechanicalmeter comprising the part in FIG. 4C or the encapsulated parts in FIGS.6C and 6D, in a three phase dual-tariff application, measuring positiveenergy flow only; and

FIG. 11A shows a schematic illustration of an example electromechanicalmeter comprising the device in FIG. 7D in a single phase application,measuring positive energy flow only:

FIG. 11B shows a schematic illustration of an example electromechanicalmeter comprising the device in FIG. 7C in a single phase application,measuring both positive and negative energy flow; and

FIG. 11C shows a schematic illustration of an example electromechanicalmeter comprising the device in FIG. 7C in a single phase dual-tariffapplication, measuring positive energy flow only; and

FIG. 11D shows a schematic illustration of an example electromechanicalmeter comprising the device in FIG. 7D in a three phase application,measuring positive energy flow only; and

FIG. 11E shows a schematic illustration of an example electromechanicalmeter comprising the devices in FIGS. 7C and 7D in a three phaseapplication, measuring both positive and negative energy flow; and

FIG. 11F shows a schematic illustration of an example electromechanicalmeter comprising the devices in FIGS. 7C and 7D in a three phasedual-tariff application, measuring positive energy flow only; and

FIG. 12 shows a schematic representation of a network of systemscomprising devices according to the disclosure; and

FIG. 13 shows a planar device positioned near a current carryingconductor and the magnetic field lines generated by the conductor;

FIGS. 14A, 14B, 15, 16A to 16D, 17 and 18 show miscellaneousnon-limiting examples of a planar part of a device according to thepresent disclosure containing magnetic field sensors arranged inproximity to a shaped current carrying conductor.

In the drawings, like reference numerals are used to indicate likeelements.

A device according to the present disclosure may provide a measure of aquantity dependent on the current through an electrical conductor (suchas by way of a non-limiting example only, power or reactive power) usingmeasurement provided by a sub-system comprising sensing circuitrycontaining sensors arranged adjacent to the electrical conductor. Insome examples, the sensing circuitry is maintained in a fixed and spacedrelationship to the electrical conductor by an encapsulating andinsulating material, so all calibration can be performed duringmanufacture and no calibration by the user is required.

In some examples, a device according to the present disclosure may beconfigured so that the sub-system may comprise at least onesemi-conductor substrate.

In some examples, a device according to the present disclosure may beconfigured so that the sensors may be magnetic field sensors.

In some examples, a device according to the present disclosure may beconfigured so that the magnetic field sensors may be Hall elements.

Alternatively or additionally, a device according to the presentdisclosure may be configured to be mounted in an external module or onan external circuit board (such as, by way of a non-limiting exampleonly, a Printed Circuit Board (PCB)), with the electrical conductoreither forming a part of the external module or circuit board or beingexternal to it, and calibration by the end user after final assembly maybe necessary.

In the context of the present disclosure, it may be provided a devicefor measuring a quantity dependent on the current through an electricalconductor which integrates both the current and the voltage sensors andthe processing circuitry for calculation of the quantity in a small formfactor, with, in some examples, a diameter of only a few millimetres.

Alternatively or additionally, a device according to the presentdisclosure may not need a large number of external components. This mayallow cheaper cost of manufacturing and less space usage.

A device according to the present disclosure may be small enough to beused in applications where space is at a premium, and may—together withall the required external components—fit into miniaturized devices whereno existing power measurement device will fit (with the socket of alight bulb and an electrical plug as non-limiting examples), and may beinexpensive enough to be used in applications where cost is an issue,such as high volume low cost consumer devices (with a light bulb and anelectrical plug as non-limiting examples).

Alternatively or additionally, a device according to the presentdisclosure may measure the quantity accurately. Alternatively oradditionally, a device according to the present disclosure may containall the required metrology compensations. Alternatively or additionally,a device according to the present disclosure may further comprise amodule for compensation of temperature coefficients of current and/orvoltage sensing elements and/or other sources of temperature dependence,such as the mechanical assembly. Alternatively or additionally, a deviceaccording to the present disclosure may further comprise a module forcompensation of offsets by the current and/or voltage sensors and/orother analogue electronics. Alternatively or additionally, a deviceaccording to the present disclosure may be configured to be aplug-and-play device, and in some examples no calibration of the devicemay be necessary. This may allow ease of implementation by a user, mayallow use by users who have no metrology know-how and may further allowease of use in retrofit situations.

Alternatively or additionally, a device according to the presentdisclosure may include means for rejection of stray electromagneticfields. In such examples, the device may not need to be shielded toprovide an accurate reading. In some examples, this may be achieved bymeans which completely reject all stray magnetic fields with spatialdependence which is polynomial of a given bounded order, and thusproviding good rejection of all fields whose spatial dependence may bewell approximated by a polynomial of a given bounded order. In someexamples, this may be achieved by the device containing one or moremagnetic field sensors to measure the current contactlessly by sensingthe magnetic field the current generates, with the number and thespatial arrangement of the magnetic field sensors in the device and theway the outputs of the magnetic field sensors are combined chosen so asto completely reject stray electromagnetic fields with spatialdependence which is polynomial of a given bounded order.

Alternatively or additionally, a device according to the presentdisclosure may include means of maximizing the strength of the usefulsignal while rejecting stray electromagnetic fields without any need forexternal shielding. In some examples, this may be achieved with specialshaping of the current conductor and a special spatial arrangement,which in some examples may be fixed, between the magnetic field sensorsand the current conductor.

Alternatively or additionally, a device according to the presentdisclosure may sense current contactlessly, giving an isolated readingwithout needing any additional isolation circuitry.

Alternatively or additionally, a device according to the presentdisclosure may have low levels of noise and may not require the use of afield concentrator.

Alternatively or additionally, a device according to the presentdisclosure may in some examples simultaneously measure severalquantities dependent on the current through a conductor, eitherintegrating several measurement apparatuses or time multiplexing asingle measurement apparatus, or containing several measurementapparatuses and time multiplexing some of them.

Thus, a device according to the present disclosure may in some examplesprovide an accurate measurement of both electrical real power andreactive power.

Alternatively or additionally, a device according to the presentdisclosure may in some examples provide also an accurate measurement ofthe RMS line voltage.

Alternatively or additionally, a device according to the presentdisclosure may in some examples provide also an accurate measurement ofapparent power and/or RMS line current and/or power factor and/or phaseangle and/or line frequency, with measurements performed in a novel way.

Alternatively or additionally, a device according to the presentdisclosure may in some examples further comprise a temperature sensor,permitting each system of which it forms a part to also measuretemperature, which may be useful in a number of applications, such as ina house heating and/or thermostat system.

Alternatively or additionally, a device according to the presentdisclosure may be configured to operate in a normal mode or in a sleepmode. The sleep mode may allow low power operation in which the devicemay consume very little power, e.g. as a non-limiting example,microwatts only of power, thus potentially enhancing the life span of apower supply and/or reducing power consumption. The device may beconfigured to operate in the sleep mode during a great proportion of thetotal operation of the device, e.g. as a non-limiting example, 90% ofthe total time of operation, whilst still providing accuratemeasurement.

Alternatively or additionally, a device according to the presentdisclosure may in some examples comprise one or more input-outputs whichmay be unidirectional (inputs or outputs) or bidirectional(input-outputs) and which may in some examples be analog, digital ormulti-level input-outputs and may in some examples form a part of ananalog, digital or mixed signal interface (such as, by way of anon-limiting example only, a Serial Peripheral Interface (SPI)). In someexamples, some of these outputs may signal the occurrence of an event(such as, by way of a non-limiting example only, a fixed quantum of oneof the quantities the device measures being reached), which may by wayof non-limiting examples be done either by outputting pulses or cyclingtransitions between a finite set of fixed voltage levels (such a by wayof a non-limiting example, high and low). Alternatively or additionally,in some examples, some of these outputs may provide readings ofcontinuous variables, such as by way of a non-limiting example, a PulseWidth Modulated (PWM) output, with pulse width related to the value ofone of the quantities the device measures, or an analogue voltageoutput, with the voltage related to the value of one of the quantitiesthe device measures. Alternatively or additionally, in some examples,some of these outputs may be configured to drive a mechanical displaydirectly. Alternatively or additionally, in some examples, some of theseoutputs may provide readings of discrete variables (such as, by way ofnon-limiting examples only, the direction of energy flow; an indicatorthat the total amount of power flow is below a certain threshold(sometimes referred to as “creep current” or “creep power”)).Alternatively or additionally, in some examples, at least one of theseoutputs may signal the occurrence of the end of an AC mains voltagecycle and that the device has data available to read. Alternatively oradditionally, in some examples, some of these inputs may select andcontrol various functions of the device.

Alternatively or additionally, a device according to the presentdisclosure may provide a reading of the signed quantities it measures ona single output, or it may provide them on two outputs, one for thepositive part and one for the negative part.

Alternatively or additionally, a device according to the presentdisclosure may in some examples incorporate at least one communicationline, allowing applications not only in single phase energy measurement,but also polyphase energy measurement, by using several devices (in someexamples, one per phase) with the several devices communicating betweeneach other using at least one (and in at least some non-limitingexamples, a single) communication line and calculating the total poweramong the phases automatically without the use of any additionalcomponents.

Alternatively or additionally, a device according to the presentdisclosure may provide built-in support for multi-tariff metering,providing a separate output or outputs for each tariff and may alsoprovide a tariff select input.

Alternatively or additionally, a device according to the presentdisclosure may be configured to have input-output signals compatiblewith Complementary Metal-Oxide-Semiconductor (CMOS) and/orTransistor-Transistor Logic (TTL).

Alternatively or additionally, in some examples, a device according tothe present disclosure may be used in conjunction with external orinternal circuitry providing either wireless connectivity (with WiFi,Bluetooth or mobile telephony as non-limiting examples) or wiredconnectivity (with powerline communications or Ethernet as non-limitingexamples), which may be useful in many applications (with any network ofinter-connected devices or Internet-of-Things applications asnon-limiting examples). When so used, the whole assembly may be smallenough to fit into a miniaturized device (with the socket of a lightbulb, an electrical plug and an electrical socket as non-limitingexamples), and may be inexpensive enough to permit use in high volumelow cost consumer devices (with a light bulb, an electrical plug and anelectrical socket as non-limiting examples).

In some examples, a device according to the present disclosure comprisesa sensing and processing sub-system, an electrical conductor configuredto conduct a current and means of maintaining the electrical conductorin a fixed and spaced relationship to the sensing and processingsub-system. In some examples this may be achieved by encapsulating thesensing and processing sub-system and the electrical conductor in acommon enclosure. In other examples, the sensing and processingsub-system may be encapsulated and affixed (such as by way ofnon-limiting examples only, in an integrated circuit package, as achip-on-board (COB) or as flip chip) to an external module or circuitboard (such as, by way of a non-limiting example only, a PCB), with theelectrical conductor being either a track comprising a part of themodule or circuit board, or a conductor external to the module orcircuit board. One of the numerous advantages of the device according tothe present disclosure is that calibration of the device is simplebecause of the fixed relationship between the electrical conductor andthe sensing and processing sub-system, and that in some examples, fullcalibration can be performed during manufacturing, with no furthercalibration by the user of the device being required.

A device according to the present disclosure may be an inexpensive,simple but accurate way to measure quantities dependent on the currentthrough a conductor (such as, by way of non-limiting examples only,power and reactive power), because of the small size and the absence ofrequirements for external components.

A device according to the present disclosure may have numerousapplications and may be implemented in numerous systems. A deviceaccording to the present disclosure may be implemented, as non-limitingexamples, in an electrical socket connected to the mains; an electricalplug configured to be connected to the mains via an electrical socket;an electrical adapter configured to be connected to the mains via anelectrical socket and/or electrical plug; a light bulb; an electricalmeter; a domestic appliance; any electrical device; any combination ofthe foregoing or in any smart system which may form part of a network ofinter-connected devices or an Internet-Of-Things (IoT).

FIGS. 1 to 3A and 7 to 7F illustrate examples of a device 10 accordingto the present disclosure. In these examples, the device 10 comprises:

-   -   at least one electrical conductor 12 (which by way of        non-limiting examples only, may be a wire, a busbar, a printed        circuit board (PCB) track; and may, by way of non-limiting        examples only, be a simple straight conductor or may be shaped,        as discussed further below) to conduct a current;    -   at least one sensing and processing sub-system 11 (which by way        of a non-limiting example only, in these figures is a        semiconductor substrate) for each electrical conductor 12,        comprising a sensing face arranged to be placed adjacent to its        corresponding conductor 12;    -   an insulating substance or substances 13 (which may in some        non-limiting examples be a substantially rigid material or        materials; and which by way of non-limiting examples only, may        in some examples be a blob seal or an integrated circuit        package, or a part of a PCB) surrounding and/or encapsulating        the sub-systems 11;    -   means to maintain each electrical conductor 12 in a fixed and        spaced relationship adjacent to its corresponding sub-systems        11.

In the examples in FIGS. 1 to 18 and 7 to 7F, the fixed and spacedrelationship between each conductor and its corresponding sub-systems 11is maintained by virtue of being incorporated in the same rigidencapsulating material 13, with electrical conductor 12 being bonded tothe integrated circuit package encapsulating its correspondingsub-system 11. In examples in FIGS. 2 to 2C, the fixed and spacedrelationship between each conductor and its corresponding sub-systems 11is maintained by virtue of both being affixed to the rigid element 15(which may, by way of a non-limiting example only, be a module or acircuit board and which by way of a non-limiting example only, in thesefigures is a PCB; and which may further in some non-limiting examplesform a part of one of the insulating materials 13).

In some examples, the device 10 may further comprise additionalcomponents which may be internal or external to an insulating materialor materials 13 encapsulating the sub-system 11. In some examples, adecoupling capacitor may be included (denoted C in FIGS. 1B and 8 to9F). Additionally or alternatively, in some examples, at least onereference resistor, which may be a high precision resistor, may beincluded (denoted Rref in FIGS. 1B and 8 to 9F). Additionally oralternatively, some examples may not require and/or not incorporate areference resistor. Additionally or alternatively, in some examples,voltage sensing resistors which internally connect one of the inputs ofthe sub-system 11 to its corresponding electrical conductor 12, may beincluded (denoted Rin in FIGS. 1B and 8 to 9F). In other examples, othercomponents may be included.

In some examples, the conductor 12 and the sub-system 11 may be shapedto allow thermal expansion of the conductor 12 with respect to thesub-system 11 during normal operation.

The insulating substance or substances 13 are configured to insulate theelectrical conductor 12 from the sub-system 11.

FIGS. 4 to 4E represent examples of parts (which by way of non-limitingexample only, in these figures are semi-conductor substrates) accordingto the present disclosure which may form the sub-system 11, and FIGS. 6to 8F represent semi-conductor substrates in FIGS. 4 to 4E encapsulatedin integrated circuit packages.

The sub-system 11 contains the means to measure at least one quantity Qrelated to the current through the electrical conductor 12 (withcurrent, rectified current, instant power and instant reactive powerbeing non-limiting examples of quantity Q).

The sub-system 11 will now be further described with reference to theenclosed figures, specifically with reference to FIG. 5. It is to beunderstood that the blocks in FIG. 5 may not necessarily be arrangedwithin sub-system 11 in the same spatial relationships as in FIG. 5,that they may or may not be spatially interleaved and that not all theexamples according to the present disclosure include all the blocks inFIG. 5.

In some examples, the sub-system 11 may comprise sensing circuitry 112comprising a plurality of magnetic field sensors 113, each providing atleast one output. The sensing circuitry 112 may be configured to providea measure of quantity Q as a combination (which may in some non-limitingexamples only be a linear combination, i.e. a weighted sum and/ordifference) of magnetic field sensor outputs. To that effect, thesub-system 11 may further comprise a combination module 124 forcombining the outputs of the magnetic field sensing elements 113.

In some examples, the magnetic field sensors 113 are arranged so as tobe adjacent to an electrical conductor 12 in a normal mode of operationof the device 10.

In some examples, at least some of the magnetic field sensors 113 may beHall elements and their outputs may be Hall element output voltages.

The sub-system 11 may further comprise a voltage sensing input 114 forsensing a voltage potential (relative to some other voltage potentialwhich may in some non-limiting examples be the ground voltagepotential). In some examples, this input may be connected to the voltagepotential via a resistor (which may, by way of a non-limiting exampleonly, be a high resistance resistor), thus generating a current (whichmay, by way of a non-limiting example only, be a small current) into orout of the input 114 which is related to the voltage potential. In someexamples, the voltage potential may be a voltage potential associatedwith a predetermined conductor. In some examples, the predeterminedconductor may be conductor 12. In other examples the predeterminedconductor may be another conductor (by way of a non-limiting exampleonly, where conductor 12 is the neutral line and the pre-determinedconductor is a live conductor).

In some examples, the magnetic field sensors 113 are arranged to bebiased by a current derived from and/or related to the current in or outof input 114 and/or thus related to the voltage potential, so that theoutput from the magnetic field sensors is related to current throughconductor 12 and/or the voltage potential. In some examples, the biascurrent may be taken to be proportional to the voltage potential of theelectrical conductor 12, so that the output from the magnetic fieldsensors and/or the combination module 124 is related to the instantpower through conductor 12. In other examples, the bias current may betaken to be proportional to the voltage potential of the electricalconductor 12, phase shifted by 90°, so that the output from the magneticfield sensors and/or the combination module 124 is related to theinstant reactive power through conductor 12. In other examples, the biascurrent may be taken to be constant, so that the output from themagnetic field sensors and/or the combination module 124 is related tothe current through conductor 12. In other examples, the bias currentmay be chosen in a different way.

As a non-limiting example only, the maximum current through conductor 12may be of the order of a few milliamperes to a few hundred amperes; byway of a non-limiting example, the device in FIG. 1 is configured formaximum current of 15 A. As a non-limiting example only, the maximumvoltages may be of the order of a few hundreds of millivolts to a fewthousands of volts; by way of a non-limiting example only, the device inFIG. 1 may be configured for typical voltage of about 110V, 220V or315V.

Alternatively or additionally, the sub-system 11 may in some examplesfurther comprise a zero-crossing detection module 119 configured todetect at least some of the zero-transitions of the voltage sensinginput 114, which correspond to zero-transitions of the AC voltage (byway of a non-limiting example only, in some examples, it may detectrising-edge zero-transitions, in some examples, it may detectfalling-edge zero-transitions, and in some examples it may detect both),and may also detect whether they are rising-edge transitions orfalling-edge transitions. The reading of the zero-crossing detectionmodule 119 may be used to detect the end of an AC voltage cycle and/orthe end of an AC voltage half-cycle. In some examples, the sub-system 11may provide an output disclosing at least some of the zero-transitions,allowing systems incorporating the sub-system 11 to measure the timeinterval ΔT between zero-transitions of the AC voltage and/or theduration of an AC voltage cycle.

The sub-system 11 may further comprise integration circuitry 116configured to integrate the measure of quantity Q as output by thesensing circuitry 112 and/or the combination module 124 over a completeor a fraction of an AC voltage cycle period. The integration circuitry116 may in some examples comprise at least one capacitor configured tobe charged by a voltage proportional to the measure of quantity Q duringthe AC voltage cycle period.

In some examples, the integration circuitry 116 is configured tointegrate the measure of quantity Q during both halves of a complete ACvoltage cycle period by inverting the polarity of the integration of themeasure of quantity Q when the AC voltage, for example, changespolarity. The change of polarity of the AC voltage may be detected usinga measuring obtained from a zero-crossing module 119.

Additionally or alternatively, the integration circuitry 116 maycomprise two capacitors: i.e. one capacitor integrating the measure ofquantity Q or its negative over a first half of a complete AC voltagecycle period (for example the positive half of the AC voltage cycleperiod), and another capacitor integrating the measure of quantity Q orits negative over a second half of a complete AC voltage cycle period(for example the negative half of the AC voltage cycle period), thedevice being configured to measure the sum or difference of bothintegrations, as may be appropriate.

In some examples, the integration circuitry 116 may be configured tointegrate the measure of quantity Q over a major fraction of a completeAC voltage cycle period (preferably by way of a non-limiting exampleonly, 99.95%), and then output data and reset the sub-system 11 (forexample, discharging some capacitors) during another fraction of thecomplete AC voltage cycle period. The output data corresponding to thecomplete AC voltage cycle period may be an extrapolation of the datameasured during the major fraction of the AC voltage cycle period to thecomplete AC voltage cycle period. Once the data is output and thesub-system reset after expiration of the minor fraction of the completeAC voltage cycle period, the sub-system 11 is ready for measurementduring another AC voltage cycle period.

In some examples, the integration circuitry 116 is configured topreferably always reset (for example, discharge capacitors) after areading to ensure accurate reading (for example, ensuring that thecapacitors are always discharged at a beginning of a measurementperiod).

Alternatively or additionally, in some examples, the integrationcircuitry 116 may comprise more than one module (for example, eachmodule comprising at least one capacitor). In some examples, integrationcircuitry 116 may cycle between the modules so that a different modulemay be arranged to integrate the measured quantity Q over one completeAC voltage cycle period than the module that was arranged to integratedit over the preceding complete AC voltage cycle period. Alternatively oradditionally, in some examples, a first one of the modules may bearranged to integrate the measured quantity Q over a complete AC voltagecycle period and then be used to initialize a second one of the modules,which acts as a buffer, before resetting the first module at thebeginning of a new AC voltage cycle period and then using the firstmodule or a third one of the modules to perform the integration over thefollowing complete AC voltage cycle period.

Additionally or alternatively, in some examples, the sub-system 11 mayfurther comprise a module configured to provide an offset compensationfunction.

In some examples, the sub-system 11 may further comprises a temperaturesensor 123. This is useful in a number of applications, by way of anon-limiting example, allowing systems incorporating device 10 to form apart of a house heating and/or thermostat system.

In some examples, the sub-system 11 may further comprise a module 118configured to provide a temperature compensation function.

The circuitry of the sub-system 11 may be at least partly comprised of asignal processor 111. In the context of the present disclosure, thesignal processor 111 may be an analog processor only, a digitalprocessor only, or it may be a mixed signal processor. Additionally oralternatively, in some examples, the signal processor 111 may furthercomprise means to quantize at least one of the quantities (with theenergy, reactive energy and the integral of rectified voltage asnon-limiting examples) measured by the sub-system 11. Additionally oralternatively, in some examples, the signal processor may produce bothpositive and negative quanta of signed quantities. Additionally oralternatively, in some examples, the signal processor 111 may furthercomprise at least one up-down counter to count one of these quanta orone of these pairs of quanta (such as by way of a non-limiting exampleonly, the pair of positive and negative quanta of a quantity).Additionally or alternatively, in some examples, the up-down counter maybe configured with a threshold, upon the reaching of which it may insome examples generate larger quanta, and in some examples pairs oflarger quanta (corresponding to positive and negative larger quanta),after which the up-down counter may be reset. Alternatively oradditionally, in some examples, the value of these quanta may be set tocorrespond to a given fixed frequency of quanta per kWh, which may insome examples be configurable.

In some examples, the sub-system 11 may further comprise calibrationcircuitry 117 for adjusting gain and/or offset compensation and/or otherparameters of the sensing circuitry 112 (by way of a non-limitingexample only, the calibration of at least one amplifier of the sensingcircuitry 112) and/or the integration circuitry 116 and/or thezero-crossing detection module 119 and/or the signal processor 111and/or the temperature compensation of the temperature compensationmodule 118. In some examples (with examples where the current conductor12 forms an integral part of device 10 assembly as a non-limitingexample), these parameters may be fully calibrated during device 10manufacturing, requiring no further calibration by the user. In otherexamples (with examples where the current conductor 12 does not form anintegral part of device 10 assembly as a non-limiting example), theseparameters may be left to the user to calibrate (in some non-limitingexamples, after final assembly of device 10 and conductor 12). In someexamples, two sets of calibration parameters may be provided, some to bepre-calibrated during manufacturing and some provided to the user tooffer some adjustability of the device.

In some examples, the calibration circuitry 117 may be arranged to storeat least one calibration parameter. The storage of the calibrationelement may be performed in a volatile or non-volatile memory forming apart of the sub-system 11, such as, as non-limiting examples, aprogrammable element (which may in some examples be re-programmable, ormay in some examples be only programmable once), and/or a mechanicallyfusible element, a Zener diode, a laser tuneable element and/or anycombination of the foregoing.

It is understood that one of the numerous advantages of the integrateddevice according to the present disclosure is that calibration of thedevice 10 is simple and can be performed during a method ofmanufacturing, prior to packaging for dispatch, because of the fixedrelationship between the electrical conductor 12 and the sub-system 11.

In some examples, the sub-system 11 may be configured to measure morethan one quantity Q simultaneously. The sub-system 11 may achieve thiseither by time-multiplexing the same metrology apparatus integrated intoit and measuring each such quantity Q for a portion of each AC voltagecycle, for example by high frequency multiplexing, or by means ofincorporating several similar metrology apparatuses.

Alternatively or additionally, the sub-system 11 may in some examplesfurther comprise a module to measure the integral ({tilde over (V)}) ofthe rectified AC voltage over a complete AC voltage cycle.

In some examples, the sub-system 11 may further comprise a sleep controlinput and a sleep function provided by circuitry 120 which allows, in asleep mode of operation, the device to be partially or completely shutdown. In some examples, the device 10 is arranged to partially orcompletely shut itself down at an end of a complete AC voltage cycleperiod following the assertion of a sleep input. In some examples, thedevice 10 is arranged to wake up on or shortly after the assertion of awake input and start measuring at the beginning of a following completeAC voltage cycle period (such as, by way of a non-limiting example, thenext immediately following complete AC voltage cycle period). The shutdown and/or the wake up is thus performed gracefully.

Additionally or alternatively, in some examples, the signal processor111 may further comprise input-output circuitry 115. Input-outputcircuitry 115 may comprise one or several input-output signals, some ofwhich may be unidirectional (inputs or outputs) and some of which may bebidirectional (input-outputs), some of which may be digital and/ormulti-level and/or analog, and some of which may change valuecontinuously in time and/or at discrete points in time; some of theseinput-outputs may support tri-state operation (high impedance state).

In some examples, input-output circuitry 115 may be arranged to outputthe information measured and/or determined by the sub-system 11 and toprovide input signals to control certain functions of the sub-system 11.

In some examples, the sub-system 11 and these input-outputs may beisolated from conductor 12 with the current being sensed contactlesslyand the voltage being sensed via a high resistance resistor only, withno isolators being required.

By way of non-limiting examples only, these input-output signals mayinclude pulse-width modulated (PWM) signals, pulse signals, transitionsignals and signals implementing miscellaneous analog and/or digitaland/or mixed signal interfaces.

Additionally or alternatively, in some examples, the input-outputcircuitry 115 may further comprise at least one output providing ananalog value (by way of non-limiting examples only, via an analogvoltage output, or the width of a pulse of a pulse-width modulated (PWM)output), with the value of some such outputs related to one of thequantities the sub-system 11 measures, with the amount of total energyflow over a complete AC voltage cycle, the amount of total reactiveenergy flow over a complete AC voltage cycle, the integral of therectified AC voltage over a complete AC voltage cycle and the measuredtemperature, as non-limiting examples. The relationship between theoutput value and the measured quantity may by way of non-limitingexamples be linear or affine (i.e. linear with a constant offset), or itmay take the form of some other relationship. In some examples, thevalue of these outputs may be provided on or shortly after the end of anAC voltage cycle period.

Additionally or alternatively, in some examples, the input-outputcircuitry 115 may further comprise at least one output representingevents (by way of non-limiting examples only of such an output, a pulseoutput generating pulses, or a transition output generating transitions,such as by way of non-limiting example, cycling transitions betweenfixed levels of voltages, such as, by way of a non-limiting exampleonly, between a high and a low state; by way of non-limiting examplesonly of such events being a fixed quantum of one of the quantities thesub-system 11 measures being reached, with positive and negative quantaof signed quantities potentially representing different events). In somenon-limiting examples, such an output may be able to represent more thanone kind of event (by way of a non-limiting example only, eventscorresponding to both positive and negative quanta of a quantity; by wayof a non-limiting example only, a pulse output may encode severaldifferent event types by utilizing several pulse durations, eachduration representing one event type).

Additionally or alternatively, in some examples, the input-outputcircuitry 115 may further comprise circuitry to directly drive amechanical display (which may in some non-limiting examples be acyclometer display) without any need for additional external components.In some non-limiting examples, this circuitry may provide differentialpairs of specially shaped pulse output signals.

Additionally or alternatively, in some examples, the input-outputcircuitry 115 may further comprise at least one output providing adiscrete value (by way of a non-limiting example, a digital ormulti-level output). In some non-limiting examples, these outputs allowdirect connection to a display device (such as, by way of a non-limitingexample only, an LED) in some systems (such as by way of a non-limitingexample only, electricity meters) that may require it. Two non-limitingexamples of such an output are an output indicating the currentdirection of energy flow, and an output indicating whether the amount ofpower flow exceeds a certain pre-determined fixed threshold or not. Insome non-limiting examples, the value of these outputs may be set tochange at the end of an AC voltage cycle period depending on the totalor average value of energy flow over the preceding AC voltage cycleperiod.

Additionally or alternatively, in some examples, device 10 may beconfigured to signal no power flow when the total amount of power flowis below a certain pre-determined fixed threshold.

Additionally or alternatively, in some examples, the input-outputcircuitry 115 may further comprise at least one digital interface. Insome examples, some of these interfaces may be used to provide a meansto output some of the quantities measured by the sub-system 11 and/or toselect some of sub-system 11's function and/or set some of itscalibration parameters. In some non-limiting examples, at least one ofthese interfaces may be an SPI interface, which will be known to theperson skilled in the art. In some non-limiting examples, data on someof these outputs may be made available at the end of an AC voltageperiod.

Those examples of the sub-system 11 which measure the total active (E)and reactive (E_(r)) energy flow, the integral of the rectified ACvoltage ({tilde over (V)}) over an AC voltage cycle period, and whichcontain a zero-crossing module 119, permit the device 10 and/or thesystems incorporating it to determine also the line frequency (f), theapparent energy (E_(t)) flow, the real power (P), the reactive power(P_(r)), the apparent power (P_(t)), the RMS voltage (V), the RMScurrent (I) and the power factor (cos Φ) using the following equations,which are known to those skilled in the art:

${f = \frac{1}{\Delta T}}{{Et} = \sqrt{E^{2} + {Er}^{2}}}{P = \frac{E}{\Delta T}}{\Pr = \frac{Er}{\Delta T}}{{Pt} = \frac{Et}{\Delta T}}{V = {\frac{\overset{\_}{V}}{\Delta T} \times \frac{\pi}{2\sqrt{2}}}}{I = \frac{Pt}{V}}{{\cos\Phi} = \frac{E}{Et}}$

For best accuracy, it may be advisable to totalize measurements acrossseveral mains periods before performing the above calculations.

In some examples, the device 10 may contain a plurality of at least twofield sensors H₀, . . . , H_(n) used to measure at least one quantity Qdependent on the field, with the output of the field sensors beingcombined in a way which offers at least a partial rejection of strayfields.

In some non-limiting examples, all stray fields whose spatial dependenceis polynomial of any given fixed bounded degree are rejected.

In some non-limiting examples, each field sensor H may output a scalarsignal V(H) which is dependent on the field at the point of the fieldsensor.

In some non-limiting examples, the device 10 may be configured in such away and operated in such conditions that each such signal V(H) dependsapproximately linearly on the field at the point of the field sensor towithin the desired accuracy.

In some non-limiting examples, V(H) may depend on a component of thefield in a given direction only, such as a direction parallel to acertain line (or equivalently, perpendicular to a certain plane).

In some non-limiting examples, quantity Q may be measured by combiningthe outputs V(H₀), . . . , V(H_(n)) in a linear way so that

Q=T(Q′)

Q′=λ ₀ V(H ₀)+ . . . +λ_(n) V(H _(n))

for some constant weightings λ₀, . . . , λ_(n) and some transformationT.

Suppose that an integer D≥0 Is given. In some examples, field sensorsH₀, . . . , H_(n) may be arranged spatially and their weightings λ₁, . .. , λ_(n) chosen in such a way that their spatial co-ordinates(x₀,y₀,z₀), . . . , (x_(n),y_(n),z_(n)) in some co-ordinate system (andif so, necessarily in every co-ordinate system) satisfy the equations:

${\sum\limits_{\ell = 0}^{n}{\lambda_{\ell}x_{\ell}^{i}y_{\ell}^{j}z_{\ell}^{k}}}==0$

for all i,j,k≥0 and i+j+k≤D. This condition is necessary and sufficientfor the plurality of field sensors H₀, . . . , H_(n) to reject all strayfields whose spatial dependence is polynomial of degree at most D. As aset of

$\begin{pmatrix}{D + 3} \\3\end{pmatrix}$

linear equations in n+1 unknowns λ₀, . . . , λ_(n) with matrix M, thisset of equations has a non-zero solution for any choice of co-ordinates(x₀,y₀,z₀), . . . , (x_(n),y_(n),z_(n)) provided that the rank r of M isat most n; and in such a case, the solution space is a vector space ofdimension n+1−r. For any spatial arrangement of sensors (x₀,y₀,z₀), . .. , (x_(n),y_(n),z_(n)), there is a unique maximum value of D for whichthis condition is satisfied, and this D is the maximum number such thatoutputs of that spatial arrangement of sensors may be linearly combinedin a non-trivial fashion so as to reject all fields whose spatialdependence is polynomial of degree at most D.

In some non-limiting examples, field sensors H₀, . . . , H_(n) may bearranged so as to be contained in a single plane and their weightingsλ₁, . . . , λ_(n) chosen in such a way that, with the co-ordinate systemchosen so that the sensors lie in the x-y plane, their planarco-ordinates (x₀,y₀), . . . , (x_(n),y_(n)) satisfy the equations:

${\sum\limits_{\ell = 0}^{\alpha}{\lambda_{\ell}x_{\ell}^{i}y_{\ell}^{j}}}==0$

for all i,j≥0 and i+j≤D. For a planar arrangement of field sensors, thiscondition is necessary and sufficient for the plurality of field sensorsH₀, . . . , H_(n) to reject all stray fields whose spatial dependence ispolynomial of degree at most D. As a set of

$\begin{pmatrix}{D + 2} \\2\end{pmatrix}$

linear equations in n+1 unknowns λ₀, . . . , λ_(n) with matrix M, thisset of equations has a non-zero solution for any choice of co-ordinates(x₀,y₀), . . . , (x_(n),y_(n)) provided that the rank r of M is at mostn; and in such a case, the solution space is a vector space of dimensionn+1−r. For any planar arrangement of sensors (x₀,y₀), . . . ,(x_(n),y_(n)), there is a unique maximum value of D for which thiscondition is satisfied, and this D is the maximum number such that thatoutputs of that planar arrangement of sensors may be linearly combinedin a non-trivial fashion so as to reject all fields whose spatialdependence is polynomial of degree at most D.

In some non-limiting examples, field sensors H₀, . . . , H_(n) may bearranged so as to be contained in a single line and their weightings λ₁,. . . , λ_(n) chosen in such a way that, with the co-ordinate systemchosen so that the sensors lie in the x-line, their linear co-ordinatesx₀, . . . , x_(n) satisfy the equations:

${\sum\limits_{\ell = 0}^{n}{\lambda_{\ell}x_{\ell}^{i}}}==0$

for all i≥0 and i≤D. For a linear arrangement of field sensors, thiscondition is necessary and sufficient for the plurality of field sensorsH₀, . . . , H_(n) to reject all stray fields whose spatial dependence ispolynomial of degree at most D. As a set of D+1 linear equations in n+1unknowns λ₀, . . . , λ_(n) with matrix M, this set of equations has anon-zero solution for any choice of co-ordinates x₀, . . . , x_(n)provided that the rank r of M is at most n; and in such a case, thesolution space is a vector space of dimension n+1−r. For distinct x₀, .. . , x_(n), this holds if and only if n≥D+1. For any linear arrangementof sensors x₀, . . . , x_(n), outputs of that linear arrangement ofsensors may be linearly combined in a non-trivial fashion so as toreject all magnetic fields whose spatial dependence is polynomial ofdegree at most D=n−1. In the case of D=n−1, the λ₀, . . . , λ_(n) aregiven by:

$\lambda_{i}=={\frac{1}{\prod_{{0 \leq j \leq n} \land {j \neq i}}\left( {x_{j} - x_{i}} \right)} \cdot C}$

where C is an arbitrary constant.

In particular, it will be noted that in this case, the λ₀, . . . , λ_(n)have alternating signs if x₀, . . . , x_(n) are ordered, i.e., if x₀< .. . <x_(n).

In some non-limiting examples, field sensors H₀, . . . , H_(n) may bearranged so as to be contained in a single fine and so that adjacentpairs of sensors are equidistant, and their weightings λ₀, . . . , λ_(n)may, with the numbering of sensors chosen so that H₀, . . . , H_(n) arearranged in order left-to-right on the line, satisfy the equations

$\lambda_{i}=={\left( {- 1} \right)^{i} \cdot \begin{pmatrix}n \\i\end{pmatrix}}$

For this arrangement of field sensors, this condition is (up tomultiplication by a constant) necessary and sufficient for the pluralityof field sensors H₀, . . . , H_(n) to reject all stray fields whosespatial dependence is polynomial of degree at most n−1.

By way of a non-limiting example, n=2 gives (λ₀, . . . , λ_(n))=(1,−1),n=3 gives (λ₀, . . . , λ_(n))=(1,−2,1), n=4 gives (λ₀, . . . ,λ_(n))=(1,−3,3,−1) and n=5 gives (λ₀, . . . , λ_(n))(1,−4,6,−4,1).

In some non-limiting examples, at least one of the field sensors H₀, . .. , H_(n), say sensor H, whose output weighting is λ may comprise ofseveral field sensors H¹, . . . , H^(n) located in spatially nearlyidentical location with weightings λ⁽¹⁾, . . . , λ^((n)) such that λ⁽¹⁾+. . . +λ^((n))=λ.

In some non-limiting examples, where λ₀, . . . , λ_(n) are all smallintegers, field sensors H₀, . . . , H_(n), may comprise of |λ₀|+ . . .+|λ_(n)| identical sensors in n+1 groups of |λ₀|, . . . , |λ_(n)|sensors, respectively, in spatially nearly identical location, whoseweightings are all the same except for the sign.

These spatial arrangements and weightings of field sensors H₀, . . . ,H_(n) give excellent rejection of stray fields. For example, two casesof common stray electromagnetic fields are AC magnetic fields from adistant source, and low frequency AC magnetic fields generated by anearby current conductor. Supposing that a single magnetic field sensorH₀ gives an output of amplitude A when exposed to an AC field generatedby a distant source of angular frequency {tilde over (ω)}, propagatingin a direction at an angle θ to the line of the sensors, with ω={tildeover (ω)}·cos θ, a linear equidistant array of magnetic field sensorsH₀, . . . , H_(n) whose outputs are combined according to the presentdisclosure, where the distance between the extreme pair of sensors is d,gives an output of amplitude A times

${❘{2\sin\frac{\omega d}{2{nc}}}❘}^{n}$

where c is the speed of light. Some values of this attenuation for thenon-limiting example d=3 mm are given in Table 1. This attenuation ismonotonic for 0≤ω≤ncπ/d and equals 1 at ω=ncπ/3d.

TABLE 1 f [Hz] n = 1 n = 2 n = 3 n = 4  25k 1.5708 × 10⁻⁴% 6.1685 ×10⁻¹¹% 1.43548 × 10⁻¹⁷% 2.37815 × 10⁻²⁴% 250k 1.5708 × 10⁻³% 6.1685 ×10⁻⁹%  1.43548 × 10⁻¹⁴% 2.37815 × 10⁻²⁰%  2.5M 1.5708 × 10⁻²% 6.1685 ×10⁻⁷%  1.43548 × 10⁻¹¹% 2.37815 × 10⁻¹⁶%   25M 1.5708 × 10⁻¹% 6.1685 ×10⁻⁵%  1.43548 × 10⁻⁸%  2.37815 × 10⁻¹²% 250M 1.5708% 6.1685 × 10⁻³% 1.43547 × 10⁻⁵%  2.37815 × 10⁻⁸%   2.5 G 15.6918% 0.61653% 1.43498 ×10⁻²%  2.37754 × 10⁻⁴%    5 G 31.2869% 2.46233% 0.114681% 3.80113 ×10⁻³%   7.5 G 46.6891% 5.52602% 0.386385% 1.92185 × 10⁻²%    10 G61.8034% 9.7887% 0.913679% 6.06308 × 10⁻²%  12.5 G 76.5367% 15.2241%1.77903% 0.147682%   15 G 90.7981% 21.7987% 3.06258% 0.305369%   25 G norejection 58.5786% 13.8701% 2.31773% nc/2 d   50 GHz  100 GHz 150 GHz 200 GHz nc/6 d 16.7 GHz 33.3 GHz  50 GHz 66.7 GHz

Supposing that a single magnetic field sensor H₀ gives an output ofamplitude A when exposed to a low frequency AC field generated by anearby conductor, a linear equidistant array of magnetic field sensorsH₀, . . . , H_(n) whose outputs are combined according to the presentdisclosure, where the distance between the extreme pair of sensors is d,gives an output of amplitude αA, where α is some attenuation factor.Supposing the interfering conductor is located perpendicular to thesensor array at a distance horizontally x from the sensor at oneextreme, and distance z away from the plane of the sensors. Table 2tabulates the attenuation factor α in some examples.

TABLE 2 z x [μm] [mm] n = 1 n = 2 n = 3 n = 4 70 3 49.9796% 16.6468%4.98872% 1.42345% 70 4 42.8454% 11.6791% 2.85293% 0.662836% 70 537.4925% 8.649% 1.78385% 0.349728% 70 6 33.3283% 6.66387% 1.18955%0.201772% 70 7 29.9964% 5.29239% 0.832829% 0.124503% 70 8 27.2701%4.30509% 0.605768% 0.0809614% 70 9 24.998%  3.57066% 0.454366%0.0549109% 1000 3 45.9459% 12.8776% 2.95952% 0.556672% 1000 4 40.5%  9.9% 2.06445% 0.383821% 1000 5 36%    7.69942% 1.42703% 0.24221% 1000 632.3171% 6.11087% 1.00938% 0.154558% 1000 7 29.2786% 4.94856% 0.734016%0.101608% 1000 8 26.7418% 4.08011% 0.547949% 0.0689596% 1000 9 24.5977%3.41728% 0.418726% 0.0482122% 10000 3 60.2941% 11.6394% 0.156187%0.148147% 10000 4 36.2416% 8.67202% 0.418081% 0.0676314% 10000 521.9512% 6.51978% 0.484579% 0.0213895% 10000 6 12.7072% 4.89282%0.462952% 0.00329155% 10000 7   6.42857% 3.64814% 0.405124% 0.0147685%10000 8  2.0362% 2.69442% 0.337304% 0.0186676% 10000 9  1.0929% 1.96487%0.272111% 0.0185848%

Alternatively or additionally, the current conductor 12 in device 10 maybe shaped in such a way, and may be positioned and meander spatially insuch a way in relation to the magnetic field sensors 113 in device 10that the combined output Q′ of the magnetic field sensors gives areading such that the signal generated by a magnetic field generated bya current flowing in conductor 12 is maximized.

In some examples, conductor 12 is arranged as one or more straight,curved, zigzag and/or coiled sections placed In proximity to themagnetic field sensing elements/sensors, possibly In differentorientations.

In some examples, conductor 12 may be placed close to the magnetic fieldsensors 113. By way of a non-limiting example only, in some exampleswhere the magnetic field sensors 113 lie in a plane and the conductor 12lies substantially in a plane or a thin collection of planessubstantially parallel to the plane of the sensors, the distance betweenthe two planes may be chosen to be a few micrometres only, such as forexample 50 μm-100 μm.

In some non-limiting examples where the magnetic field sensors H₀, . . ., H_(n) all lie in a single plane Π and the output of each sensor isdependent only on the component of the magnetic field at the point ofthe sensor perpendicular to Π, the conductor 12 may be shaped so as tomeander past the sensors in such a way that its effect on the magneticfield is essentially the same as that of a series of conductors c₀, . .. , c_(m) (some of which may in some non-limiting examples be linearconductors, and some of which may in some non-limiting examples beconcentric (possibly fractional number of) circular windings, ofconstant or varying radii) located in close proximity to the plane Π andsubstantially parallel to it (where some conductors may be on one sideof the plane and some on the other, or they may all be on one side). Insome, but not all, non-limiting examples, where all the sensors arecontained in a single line l, the local direction of conductors c₀, . .. , c_(m) close to the sensors may be perpendicular to the line l. Insome non-limiting examples, the conductors c₀, . . . , c_(m) may bearranged so that the current flows in some of them past the sensors indifferent directions, with the directions so chosen that the effects ofthe magnetic fields generated by the conductors on the combined outputof the sensors add constructively. Two non-limiting examplesillustrating the cases of a linear arrangement of sensors with n=5, m=4and n=5, m=9 are given in FIGS. 14A and 14B; it is noted that in otherexamples, more or fewer conductors may be present, that the conductorsmay be placed above or anywhere between the sensors, or outside thesensor line and that the directions of current flow in consecutiveconductors may or may not be alternating. In some, though not all,non-limiting examples, m is 1, 2 or 3, the conductors are straightlinear conductors perpendicular to the line of the sensors, arrangedsubstantially symmetrically around the centre of the sensors.

Some non-limiting examples of this aspect of the present disclosure areshown in FIGS. 15 to 18. Each of these figures shows:

-   -   a current conductor 12    -   a planar sensing sub-system 11, comprising magnetic field        sensors 113 H₀, . . . , H_(n).

FIGS. 15 to 16D show non-limiting examples which can be implementedeither with the current conductor 12 being an external shaped busbar, orby encapsulating the whole assembly, as an integrated system. FIG. 15shows a non-limiting example arrangement containing n+1 collinearmagnetic field sensors 113 and a conductor 12 appearing essentially astwo (2) straight conductors orthogonal to the line of the sensors; inFIG. 15, n=2 and the conductors are shown as passing through themid-points of the sensors, although neither condition is necessary, ornecessarily optimal in practice. The optimal placement of the conductorsdepends on the spacing between the conductor 12 and the plane of themagnetic field sensors 113 and is easily determined. FIGS. 16A and 16Bshow a non-limiting example arrangement containing n+1 collinearmagnetic field sensors 113 and a conductor 12 appearing essentially as 2m straight conductors orthogonal to the line of the sensors, for n=m=2and n=m=3, respectively. FIGS. 16C and 18D show several non-limitingexample arrangements containing n collinear magnetic field sensors 113and a conductor 12 appearing essentially as a series of concentriccircular windings with parallel axes which are orthogonal to the line ofthe sensors, arranged so as to generate a strong combined output signalof the sensors, for 2≤n≤6.

FIG. 17 shows a non-limiting example where the current conductor 12 is ashaped track on a printed circuit board (PCB), with the sensingsub-system 11 mounted on the PCB (as a non-limiting example, in asemiconductor package, as chip on board or as flip chip). FIG. 17 showsa non-limiting example arrangement containing n+1 collinear magneticfield sensors 113 and a conductor 12 appearing essentially as m straightconductors orthogonal to the line of the sensors, for n=m=2

FIG. 18 shows a non-limiting example where the current conductor 12 is ashaped conductor forming an integral part of device 10. FIG. 18 shows anon-limiting example arrangement containing n+1 magnetic field sensorsand a conductor appearing essentially as m straight conductorsorthogonal to the line of the sensors, for n=m=2.

In FIGS. 16A, 16B, 17 and 18, we have n=m and the conductors are shownas passing at equidistant locations through the mid-points of thesensors, although neither condition is necessary, or necessarilyoptimal, in practice. The optimal value of m for a given n, and theoptimal placement of the conductors depends on the spacing between theconductor 12 and the plane of the magnetic field sensors 113 and iseasily determined.

In the examples in FIGS. 1 to 1B, 6B to 6F and 7B to 7F, the sub-system11 is a 4, 6, 8, 12 or 14-pin chip integrated in a standard integratedcircuit package such as, by way of a non-limiting example, Small-OutlineIntegrated Circuit (SOIC), Small Outline Package (SOP), Shrink SmallOutline Package (SSOP), Thin-Shrink Small Outline Package (TSSOP), etc.

Each of the terminals I/O₁, I/O₂, I/O₃, I/O₄, I/O₅, I/O₆, . . . ,I/O_(n) in the examples in FIGS. 1B, 2, 4, 5, 6 and 7 may in someexamples be assigned to one of a number of combinations of input-outputsignals of the sub-system 11 (with AOUT_(i), PWMOUT_(i), POUT_(i),TOUT_(i), CPOUT_(i), CNOUT_(i), DIR, CREEP, SCLK, MOSI, MISO, SS, IRQ,COMM, SLEEP, PROG, SEL, and TSEL in FIGS. 4A, 6A and 7A as non-limitingexamples).

The signals in the examples in FIGS. 18, 2, 4 to 4E, 6 to 6F and 7 to 7Fare as follows:

-   -   VSS: connected to the negative terminal of the power supply to        the sub-system 11, which byway of a non-limiting example may        also be connected to neutral;    -   VDD: connected to the positive terminal of the power supply to        the sub-system 11 (by way of a non-limiting example only, this        may be a 5V or a 3.3V DC supply);    -   IRQ: an optional digital output which detects the ends of AC        voltage cycles, for example either upwards or downwards zero        crossings of the AC voltage line; may also indicate that the        reading on some of the other pins is available;    -   AOUT_(i): an optional output or outputs (distinguished by the        index/subscript i if there is more than one present) of an        analog voltage signal, which in some examples may be related to        the value of one of the quantities that the sub-system 11        measures (e.g. the total energy flow, the total reactive energy        flow, the time integral of the rectified voltage, and the        temperature, as non-limiting examples), at the end of the        just-ended mains voltage period, for example in some examples it        may be proportional to it; in other examples, it may be an        affine function (i.e. proportional with an offset) of it; and in        other examples it may be related to it in a different way;    -   PWMOUT_(i): an optional pulse-width-modulated (PWM) output or        outputs (distinguished by the index/subscript i if there is more        than one present), with pulse width related to the value of some        quantity that the sub-system 11 measures, where the relationship        and the quantities may be as a non-limiting example be similar        as in the case of pin AOUT_(i);    -   PROG: an optional input/output which may be used during        calibration and/or re-calibration to adjust parameters of the        sub-system 11 (with gain and/or offset and/or temperature        compensation and/or other parameters as non-limiting examples);    -   SLEEP: an optional input which may be used for a sleep input to        a sleep function configured to, in a sleep mode of operation,        partially or completely shut down the device. The sleep mode may        allow low power operation in which the device may, as a        non-limiting example, consume microwatts only of power. The        device may be configured to operate in the sleep mode during a        great proportion of the total operation of the device, e.g. as a        non-limiting example, 90% of the total time of operation, whilst        still providing accurate measurement;    -   DIR: an optional digital output indicating the current direction        of energy flow (positive or negative);    -   CREEP: an optional digital output indicating that the power flow        is below a certain predetermined fixed threshold (which may in        some examples be configurable);    -   SS, SCLK, MOSI, MISO: optional digital input/output pins        implementing the SPI interface:        -   SS: digital input pin; SPI interface slave select pin;        -   SCLK: digital input pin: SPI interface clock pin;        -   MOSI: digital input pin; SPI interface master output/slave            input pin;        -   MISO: digital output pin; SPI interface master input/slave            output pin;    -   By way of a non-limiting example only, this interface may be        used to communicate the readings of at least some of the        parameters the device 10 measures and/or determines, or to set        certain of device 10's parameters.    -   COMM: an optional inter-device communication line, for        communicating between several devices performing measurements in        different phases in a poly-phase measurement setup. In a        non-limiting example only, multiple devices measuring power in        different phases may use this single communication line to        totalize the power between phases. In a non-limiting example,        every device may output a pulse of a very short duration (to        reduce the error caused by pulse collisions sufficiently below        the required threshold of accuracy) corresponding to quanta of        energy flow, and every device may be monitoring the line and        adding up all the pulses on the line to its own count of energy        quanta.    -   VIN: a voltage sensing input pin which in a non-limiting example        application may be connected to an AC voltage line via a        resistor Rin, which as a non-limiting example may be a high        resistance resistor. In a non-limiting example, the resistance        of resistor Rin may be chosen so that an input current of a        fixed amount flows into the VIN input pin at a rated AC voltage.        In a non-limiting example, this current may be chosen somewhere        in the range between 250 μA and 1 mA, or it may take a different        value. Thus, as a non-limiting example, at a 250 μA current, Rin        may be chosen to be 880 kΩ for a 220V rated AC voltage, 440 kΩ        for a 110V rated AC voltage, 1.26 MΩ for a 315V rated AC        voltage, or another value for a different voltage.    -   POUT_(i): an optional digital output or outputs (distinguished        by the index/subscript i if there is more than one present)        outputting pulses corresponding to quanta of the time-integral        of one of the quantities Q (which may, by way of non-limiting        examples only, be power, reactive power, or the integral of the        rectified voltage) measured by device 10. In some non-limiting        examples, the pulses may be substantially rectangular-shaped        pulses. In some non-limiting examples, the pulses on at least        one such output may be of fixed time duration and representing        quanta of a single sign only. Alternatively or additionally, in        some non-limiting examples, the pulses on at least one such        output may be of one of two possible fixed time durations, one        duration corresponding to positive quanta and another fixed time        duration corresponding to negative quanta. In some non-limiting        examples, the fixed quantum and the pulse duration may be chosen        so that at the maximum possible specified value of quantity Q,        the duty cycle of this output is less than 100%. In some        non-limiting examples only, quantity Q may be the product of a        magnetic field and a current (measured in units of TAs) which is        proportional to a (by way of non-limiting examples, active or        reactive) instantaneous power. Alternatively or additionally, in        some non-limiting examples, several outputs POUT₁, . . . ,        POUT_(n) may be configured, with some of these outputs        outputting pulses corresponding to quanta of quantity Q only        when a specific tariff is selected. Alternatively or        additionally, in some non-limiting examples, the device may be        configurable to choose between several different possible values        of the quantum and pulse duration: in a non-limiting example,        this may be to permit a faster mode to use when the device is        being calibrated, to permit for faster calibration, or for the        measurement of instant power, and a slower mode, for example to        be used for energy measurement. By way of non-limiting examples        only, for a configuration of device 10 configured to work for        maximum magnetic fields of B_(max) (which by way of a        non-limiting example may be between 2 mT and 20 mT) and maximum        VIN current of I_(max) (which by way of a non-limiting example        may be between 300 μA and 1 mA), the quantum (q) and pulse        duration (t) can be chosen in any way that satisfies        t≤q/(B_(max)·I_(max)). By way of non-limiting examples, the        pulse duration may be chosen in the range 5 μs-30 ms; and the        quantum in the range 300 pTAs-4 μTAs. Clearly, these are meant        to be non-limiting examples and entirely different values may be        appropriate depending on the application;    -   CPOUT_(i), CNOUT_(i): an optional digital output or outputs        (distinguished by the index/subscript i if there is more than        one present) outputting shaped pulses corresponding to quanta of        the time-Integral of a product of a magnetic field and a current        (measured in units of TAs) which are proportional to a (by way        of non-limiting examples, active or reactive) energy flow.        Alternatively or additionally, by way of a non-limiting example,        the pulses these outputs produce may be of fixed duration (which        may, by way of a non-limiting example only, be 200 ms).        Alternatively or additionally, by way of a non-limiting example,        these outputs may come in pairs CPOUT_(i) and CNOUT_(i), where        the second output of the pair outputs a pulse immediately after        the output of the first output of the pair, has stopped        outputting a pulse, and at no other time. Alternatively or        additionally, by way of a non-limiting example, the voltage        levels and pulse shaping and duration on these outputs may be        chosen so as to be able to drive a mechanical display directly,        and the quantum may be chosen so as to output one pulse per 0.1        kWh or another quantity which provides the correct output for        the mechanical display. In some non-limiting examples, a first        pair of outputs CPOUT_(i) and CNOUT_(i) may output pulses        corresponding to positive quanta of energy flow, and a second        pair of outputs CPOUT_(i) and CNOUT_(i) may output pulses        corresponding to negative quanta of energy flow. Alternatively        or additionally, in some non-limiting examples, some pairs of        outputs CPOUT_(i) and CNOUT_(i) may output pulses only when a        particular tariff is selected.

TOUT_(i): an optional digital output or outputs (distinguished by theindex/subscript i if there is more than one present) outputtinghigh-to-low and low-to-high transitions corresponding to quanta of thetime-integral of one of the quantities H (which may in some non-limitingexamples be power, reactive power, or the integral of the rectifiedvoltage) measured by device 10. In some non-limiting examples, quantityH may be unsigned and may be represented by one such output representingquanta of a single sign only of quantity H. Alternatively oradditionally, in some non-limiting examples, quantity H may be signedand may be represented by two such outputs, the first outputrepresenting positive quanta, and the second output representingnegative quanta.

-   -   RREF: a reference current input pin present on some embodiments        or examples of the present disclosure, which in a non-limiting        example application is connected to VSS line via a resistor Rref        which In a non-limiting example may be of fixed resistance known        with a relatively high degree of accuracy. Some embodiments or        examples of the present disclosure do not require this pin.    -   SEL: an input selecting one of various functions of the device        10.    -   TSEL: an input selecting one of at least two tariffs and/or        selecting between unidirectional or bidirectional metering.

In the examples in FIGS. 4B, 6B and 7B, the output POUT may in somenon-limiting examples be configured to output power. Alternatively oradditionally, the output TOUT may in some non-limiting examples beconfigured to output the integral of the rectified voltage.

In the examples in FIGS. 4C, 6C and 7C, the input TSEL may in somenon-limiting examples be configured to have three settings (e.g. high,low and tri-state) with one state selecting tariff 1, a second stateselecting tariff 2, and a third setting selecting bidirectionalmeasurement. Alternatively or additionally, in some non-limitingexamples, the outputs POUT₁, POUT₂, CPOUT₁, CNOUT₁, CPOUT₂ and CNOUT₂may be configured to output power, with POUT₁, CPOUT₁ and CNOUT₁outputting either positive power flow or tariff 1 power flow and POUT₂,CPOUT₂ and CNOUT₂ outputting either negative power flow or tariff 2power flow.

In the examples in FIGS. 6D and 7D, the outputs POUT, CPOUT and CNOUTmay in some non-limiting examples be configured to output positive powerflow.

In the examples in FIGS. 4D. 6E and 7E, the outputs AOUT₁ and AOUT₂ mayin some non-limiting examples be configured to output two out of thefollowing four quantities: active power, reactive power, temperature,integral of the rectified voltage.

In the examples in FIGS. 4E, 6F and 7F, the outputs POUT₁ and POUT₂ mayin some non-limiting examples be configured to output positive andnegative energy flow, respectively.

A further possible example of the device in FIG. 7 is a 3-pin device,comprising pins VSS, VDD and I/O, where I/O may in some non-limitingexample bes a POUT or a PWMOUT type output, outputting energy, thusproviding an integrated plug and play 3-pin energy sensor. With a PWMOUTtype output, both energy and line frequency can be measured (the latterin some non-limiting examples being provided by rising edge transitionsof the PWM output).

It is understood that, in the context of the present disclosure and withreference to FIG. 12, the device 10 may be incorporated and/or connectedto any system 1000, in particular, as a non-limiting examples, anelectrical system 1000 configured to be connected to an AC electricitysupply 101.

In some examples, the electrical conductor 12 is connected to the ACelectricity supply, so that the electrical system 1000 is configured asa system measuring its own power consumption.

In some examples, the system 1000 further comprises a communicationmodule 102 configured to communicate with at least one external device103 and/or with at least one other electrical system, for exampleanother system 1000, in order to form a network 1003 of inter-connecteddevices (and/or form a part of the internet-Of-Things (IoT), as anon-limiting example). In some examples, the communication module 102may be at least partly integrated in the device 10.

In some examples, the system 1000 further comprises a temperature sensor123. In some examples, the temperature sensor 123 may be at least partlyintegrated in the device 10.

In some examples, the communication module 102 is configured tocommunicate the value of at least one of the parameters provided by theinput-output signals of the device 10, the temperature sensor 123 orvalues that may be derived from any combination of them.

In some examples, the communication module 102 is configured to operateaccording to a wireless communication protocol (such as Wi-Fi, Bluetoothor mobile telephony, as non-limiting examples) and/or a wiredcommunications protocol (such as a power-line communication protocol orEthernet as non-limiting examples).

The system 1000 may comprise at least one of any one of:

-   -   an electrical socket connected to the mains; or,    -   an electrical plug configured to be connected to the mains via        an electrical socket; or,    -   an electrical adapter configured to be connected to the mains        via an electrical socket and/or electrical plug; or,    -   a light bulb; or,    -   an electrical meter; or,    -   a domestic appliance;    -   a circuit breaker; or,    -   any other electrically powered device; or,    -   any combination of the foregoing.

FIGS. 9A to 9F and 11A to 11F illustrate examples of electromechanicalmeters according to the present disclosure, incorporating example powermeasurement devices according to the present disclosure, or exampleparts of power measurement devices according to the present disclosure,which may or may not be encapsulated in integrated circuit packages. Inall examples in these figures, the part or device used comprises drivingcircuitry required to generate output pulses to drive a mechanicaldisplay 16 without any external circuitry.

Each part 11 in FIGS. 9A to 9F may comprise the part in FIG. 4C used indie form and may, by way of a non-limiting example, be directly bondedto a PCB (by way of non-limiting examples, as chip-on-board (COB) orflip chip) or may alternatively comprise the part in FIG. 6C which isthe part in FIG. 4C encapsulated in a 14-pin package. Alternatively, ifit is an 8-pin part, it may alternatively comprise the part in FIG. 6D,which is the Part in FIG. 4C encapsulated in an 8-pin package.

Each device 10 in FIGS. 11A to 11F may comprise the device in FIG. 7Cwhich is the part in FIG. 4C encapsulated in a 12-pin package with anintegrated conductor. Alternatively, if it is an 6-pin device, it mayalternatively comprise the part in FIG. 70, which is the part in FIG. 4Cencapsulated in a 6-pin package with an integrated conductor.

In the examples in FIGS. 9A to 9F, the electromechanical meter comprises(with n=1 in FIGS. 9A to 9C and n=3 in FIGS. 9D to 9F; with m=1 in FIGS.9A and 9D and m=2 in FIGS. 9B, 9C, 9E and 9F):

-   -   a meter enclosure,    -   a single sided PCB, containing:        -   n×part 11 in FIG. 4C, either attached as flip chip or COB or            integrated in a package as the part in FIG. 6C or the part            in FIG. 6D        -   n×resistor Rin        -   n×resistor Rref,        -   n×decoupling capacitor C.        -   n×Voltage Dependent Resistor (VDR),        -   m×cyclometer mechanical display 16,        -   an unregulated 5V DC power supply,        -   LEDs as in each diagram,    -   n×copper busbar 12, which in some examples may be 50 mm×15 mm×1        mm, shaped,    -   n×plastic insulating foil,    -   2n+2 mounting screws.

In the examples in FIGS. 11A to 11F, the electromechanical metercomprises (with n=1 in FIGS. 11A to 11C and n=3 in FIGS. 11D to 11F:with m=1 in FIGS. 11A and 11D and m=2 in FIGS. 11B, 11C, 11E and 11F):

-   -   a meter enclosure,    -   a single sided PCB, containing:        -   n×device 10 in FIG. 7C or the device in FIG. 7D        -   n×Voltage Dependent Resistor (VDR),        -   m×cyclometer mechanical display 16,        -   an unregulated 5V DC power supply,        -   LEDs as in each diagram,    -   2n+2 mounting screws.

FIGS. 9A and 11A show examples of a complete unidirectional meter, whichmay include an LED pulse output.

FIGS. 9B and 11B show examples of a complete bidirectional single phasemeter, which may include two LED pulse outputs, an energy flow directionindication LED and an LED indicating energy flow being below a certainfixed threshold (‘meter stopped’ indicator).

FIGS. 9C and 11C show examples of a complete unidirectional single phasedual tariff meter, which may include an LED pulse output and anindication of energy flow being below a certain fixed threshold (“meterstopped” indicator), and an energy flow direction indication LED (whichmay for example be used to detect that the meter is incorrectlyconnected).

FIGS. 9D to 9F, and 11D to 11F show examples of polyphase metersconnected to polyphase mains (three phases in the examples in thesefigures), featuring one device 10 per phase, in which each of thedevices 10 comprises a single inter-chip communication line, and amodule configured to aggregate the readings provided by the individualdevices 10. FIGS. 9D and 11D show examples of complete 3-phaseunidirectional meters. FIGS. 9E and 11E show examples of complete3-phase bidirectional meters. FIGS. 9F and 11F show examples of complete3-phase unidirectional dual tariff meters.

By way of a non-limiting example, the energy measurement deviceaccording to the present disclosure may in some examples work on asingle 5V DC unregulated power supply and achieve the accuracy of ±0.5%of reading over a 1:500 dynamic range of power (over the full range ofcurrent, voltage and power factor between at least 0.5 and 1 in absolutevalue, and frequency range between 40 Hz and 5 kHz), with a temperaturecoefficient of 100 ppm/° C. over a −40° C. . . . +85° C. range, and maymeet or exceed the requirements for IEC 62053 Class 0.5S and ANSI C12.20Class 0.5 meters, exceeding all specifications for rejecting strayelectromagnetic fields, without shielding, by a substantial factor. Byway of a non-limiting example, the energy measurement device accordingto the present disclosure may in some examples consume at most 50 μW ofpower in sleep mode and approximately 30 mW of power in awake mode.

With reference to the drawings in general, it will be appreciated thatschematic functional block diagrams are used to indicate functionalityof devices, systems, modules and circuitry described herein. It will beappreciated however that the functionality need not be divided in thisway, and should not be taken to imply any particular structure ofhardware other than that described and claimed below. The function ofone or more of the elements shown in the drawings may be furthersubdivided, and/or distributed throughout devices, systems, modules andcircuitry of the disclosure. In some embodiments, aspects or examples,the function of one or more elements shown in the drawings may beintegrated into a single functional unit.

The above embodiments and examples are to be understood as illustrativeexamples. Further embodiments, aspects or examples are envisaged. It isto be understood that any feature described in relation to any oneembodiment, aspect or example may be used alone, or in combination withother features described, and may also be used in combination with oneor more features of any other of the embodiments, aspects or examples,or any combination of any other of the embodiments, aspects or examples.Furthermore, equivalents and modifications not described above may alsobe employed without departing from the scope of the invention, which isdefined in the accompanying claims.

In the context of the present disclosure, the term device may refer to apart only of the device.

Below are some additional optional features.

In the context of the present disclosure, an integrated device may beconfigured to simultaneously measure more than one quantity by way ofmode switching.

In the context of the present disclosure, an integrated device may beconfigured to measure rectified instantaneous current as a measuredquantity.

In the context of the present disclosure, an integrated device may beconfigured to derive a measure of the root-means-squared, RMS, currentof the current input. In the context of the present disclosure, themeasure of the RMS current may be derived from the integral of therectified current.

As already stated, an apparatus of the present disclosure may comprise acircuit breaker.

In some examples, the apparatus and/or the circuit breaker may furthercomprise means for switching off the mains current. In some examples,the means of switching off the mains current may comprise at least oneof.

-   -   a mechanically operated switch, such as a mechanical switch        and/or an electromagnetic switch; and/or    -   a semiconductor switch configured to perform the switching, such        as a solid state switch.

In some examples, the apparatus and/or the circuit breaker may comprisea mechanically operated switch which is electronically controlled.

In some examples, the apparatus and/or the circuit breaker may comprisea mechanically operated switch which comprises a relay.

In some examples, the apparatus and/or the circuit breaker may comprisea semiconductor switch which comprises a three-electrode semiconductordevice, such as a triac.

In some examples, the apparatus and/or the circuit breaker may beconfigured to fit inside a standard plug and/or socket, or a plug and/orsocket of substantially the same form factor as a standard plug and/orsocket.

In some examples, the apparatus and/or the circuit breaker may be of thesame form factor, or of substantially the same form factor, as astandard fuse.

In some examples, a plug or a socket may contain an apparatus accordingto any aspect of the present disclosure.

In the present disclosure, any feature of any one of a device and/orsystem and/or apparatus and/or meter and/or method and/or processorand/or computer program product may be combined with any feature orcombination of features of any one of a device and/or system and/orapparatus and/or meter and/or method and/or processor and/or computerprogram product according to the disclosure.

In some examples, one or more memory elements can store data and/orprogram instructions used to implement the operations described herein.Embodiments, aspects or examples of the disclosure provide tangible,non-transitory storage media comprising program instructions operable toprogram a processor to perform any one or more of the methods describedand/or claimed herein and/or to provide data processing apparatus asdescribed and/or claimed herein.

The activities and apparatus outlined herein may be implemented withfixed logic such as assemblies of logic gates or programmable logic suchas software and/or computer program instructions executed by aprocessor. Other kinds of programmable logic include programmableprocessors, programmable digital logic (e.g., a field programmable gatearray (FPGA), an erasable programmable read only memory (EPROM), anelectrically erasable programmable read only memory (EEPROM)), anapplication specific integrated circuit, ASIC, or any other kind ofdigital logic, software, code, electronic instructions, flash memory,optical disks, CD-ROMs. DVD ROMs, magnetic or optical cards, other typesof machine-readable mediums suitable for storing electronicinstructions, or any suitable combination thereof.

NUMERICAL REFERENCES INDEX

-   10—device-   11—measurement sub-system-   12—electrical conductor-   13—insulating material encapsulating measurement sub-system-   15—printed circuit board-   16—cyclometer display-   101—AC electricity supply-   102—communication module-   103—external device-   111—signal processor-   112—magnetic field sensing circuitry-   113—magnetic field sensing element-   114—voltage sensing input-   115—input-output circuitry-   116—integration circuitry-   117—calibration circuitry-   118—temperature compensation module-   119—zero-crossing detection module-   120—sleep function circuitry-   123—temperature sensor-   124—combination module-   1000—system integrating the device-   1003—network of inter-connected devices

I/We claim:
 1. An integrated device comprising: at least one sensingcircuitry arranged to be placed in proximity to an electrical conductorconducting a current, the at least one sensing circuitry comprising atleast one magnetic field sensing element, and the at least one sensingcircuitry configured to measure at least one quantity dependent on thecurrent as a combination of outputs of the at least one magnetic fieldsensing element caused by the current flowing through the electricalconductor; an input for sensing a measure of a voltage, wherein the atleast one magnetic field sensing element is arranged to be biased by acurrent derived from and/or related to the current into or out of theinput, such that the output from the at least one magnetic field sensingelement is related to the current through the electrical conductor andthe current into or out of the input.
 2. The integrated device of claim1, further comprising circuitry configured to provide an output measureof the at least one quantity.
 3. The integrated device of claim 1,further comprising one or more of: an offset compensation functionality,a temperature dependence compensation functionality, and a sleepfunction configured to, in a sleep mode of operation, at least partiallyshut down the device.
 4. The integrated device of claim 3, furthercomprising one or more semi-conductor substrates.
 5. The integrateddevice of claim 4, wherein the device is encapsulated in a package. 6.The integrated device of claim 5, wherein the at least one magneticfield sensing element comprises at least one Hall element.
 7. Theintegrated device of claim 1, wherein the combination of outputs is alinear combination.
 8. The integrated device of claim 1, wherein the atleast one sensing circuitry is configured to at least partially rejectstray magnetic fields.
 9. The integrated device of claim 1, wherein theat least one magnetic field sensing element is so arranged, and thecombination of the outputs so chosen, that the device at least partiallyrejects stray magnetic fields.
 10. The integrated device of claim 1,wherein the device is configured to simultaneously measure more than onequantity by one or more of: mode switching, time-multiplexing, andincorporating more than one set of the at least one magnetic fieldsensing element.
 11. The integrated device of claim 2, furthercomprising: integration circuitry configured to integrate one or more ofthe at least one measured quantity over at least a major fraction of acomplete AC cycle period of the input.
 12. The integrated device ofclaim 11, further comprising: a zero-crossing detection module toprovide a measure of 0-transitions of one or more of the input and ameasure of the input frequency.
 13. The integrated device of claim 1,wherein one or more of the at least one quantity is selected from thegroup consisting of: instantaneous power, reactive power, apparentpower, energy, rectified instantaneous current, power factor, phaseangle, and combinations thereof.
 14. The integrated device of claim 13,wherein the device is further configured to derive a measure of theroot-mean-squared (RMS) value of the input.
 15. The integrated device ofclaim 1, further comprising: at least one inter-device communicationline.
 16. The integrated device of claim 15, further comprising: amodule configured to combine quantity measurements provided by aplurality of devices, and/or configured to directly drive anelectromechanical meter.
 17. An integrated device comprising: at leastone electrical conductor to conduct a current; at least one integrateddevice for each conductor, the at least one integrated device configuredto provide a measure of at least one quantity dependent on the currentthrough the corresponding conductor; and means to maintain the at leastone integrated device insulated from the at least one electricalconductor, wherein the at least one electrical conductor is in a fixedspatial relationship with respect to its corresponding at least oneintegrated device, and wherein the at least one integrated devicecomprises at least one sensing circuitry, the at least one sensingcircuitry comprising at least one magnetic field sensing element, andthe at least one sensing circuitry configured to measure the at leastone quantity as a combination of outputs of the at least one magneticfield sensing element.
 18. The integrated device of claim 17, whereinthe at least one integrated device further comprises: an input forsensing a measure of a voltage; and circuitry configured to provide anoutput measure of the at least one quantity.
 19. The integrated deviceof claim 17, wherein one or more of the at least one electricalconductor is configured to pass past the at least one magnetic fieldsensing element at least one time, and wherein the one or moreconductors is capable of passing past the at least one magnetic fieldsensing element in different orientations when passing more than onetime.
 20. An integrated device comprising: at least one electricalconductor to conduct a current, wherein the integrated device isconfigured to provide an output measure of power, energy, or reactivepower through the at least one electrical conductor, wherein theintegrated device is encapsulated in an integrated circuit packagehaving between 3 and 8 pins, and wherein the at least one electricalconductor is one or more of bonded to and encapsulated in the integratedcircuit package.
 21. The integrated device of claim 20, wherein thedevice is configured to provide information about zero-crossings of thevoltage in the at least one electrical conductor.